@deathcracker66, try the below possible solutions one-by-one:

• Try restarting your computer and then verifying the integrity of the game cache for Arma 3.

1. Restart your computer and launch Steam
2. From the Library section, right-click on the game and select Properties from the menu.
3. Select the Local files tab and click the Verify integrity of game cache... button.
4. Steam will verify the game's files - this process may take several minutes.

• Try repairing the mod(s) via the Arma 3 Launcher:

1. Click "MODS."
2. Click the dropbox arrow next to the mod to repair.
3. Click the "..." icon.
4. Click "Repair."

• Try playing without any mods.

• Try all of the possible solutions listed on the Arma 3 Unusual process exit article on the Bohemia Interactive Community Wiki.

• Try switching to and playing on the profiling or development game branch. After downloading new data verify the integrity of the game cache. Note that the development branch may contain large and frequent updates, and you will only be able to play online multiplayer on a limited number of test servers.

• profiling branch (special performance + profiling build - requires access code: CautionSpecialProfilingAndTestingBranchArma3), alternative download of needed binary possible from Dwarden's dropbox

If the issue persists after trying all of the above possible solutions then use the Arma 3 Launcher to prepare a troubleshooting report and then upload the report to the feedback tracker for the developers to review.